The Boiler Components; Working Principle; Regulating - REMEHA Avanta 12v Installation & Service Manual

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fig. 63 Components of the Remeha Avanta
8.2

The boiler components

1. Flue / Air inlet connection
2. Flue gas measuring point
3. Heat exchanger
4. Front plate heat exchanger
5. Syphon
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6. Control panel
7. Fan
8. Air inlet tube
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9. Gas valve multiblock / Ignition transformer
10. Ignition/ionization electrode
11. Control unit
8.3

Working principle

The Remeha Avanta casing serves as a sealed air box, with
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air drawn in by the fan. On the outlet side of the fan is a ventu-
ri, into which a measured quantity of gas is injected based on
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the volume of air available. The fan speed control is depend-
ent on the settings of the external control, the advanced boiler
controller 'abc
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the temperature sensors).
This method of gas/air ratio control ensures that the gas
quantity is precisely adjusted to the air quantity. Thus creating
optimum combustion over the whole heat input range. The gas
and air is mixed in the venturi and then passes into the spe-
cially designed pre-mix burner. After combustion, the hot flue
59970LTGBW7H045
gas is directed through a specially designed, high efficiency
helicoil stainless steel heat exchanger with a large surface
area, and transfers its heat to the system water circulating
around the coils. In the condensing part of the exchanger the
water vapour in the flue gas condense within it and the heat
released during this process (the so-called latent or condens-
ing heat) is also transferred to the system water. The conden-
sate water so formed is discharged from the heat exchanger
via a siphon.

In normal operation, the boiler's flue gas discharge will produce
a visible white condensing "plume" and therefore care should
be taken when choosing a location for the terminal.
8.3.1

Regulating

The Remeha Avanta is a fully modulating boiler and can be
regulated using one or more of the following methods;
1. Open Therm – 2 wire interface compatible with the Reme-
ha Celcia 15 room compensator and the Remeha Celcia
20 outside weather compensator or with any other propri-
etor's OpenTherm
2. Open Therm thermostat in combination with an external
time clock.
3. On/Off room thermostat – volt free (on the X9 terminal
strip).
4. On/Off room thermostat – 230 V (on the X2 terminal strip).
5. 230 V Switching time clock – compatible with the Remeha
two channel time clock or with any other appropriate time
clock. For further details see par. 2.8.
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' and the prevailing temperatures (measured by
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controls.
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